Apparatus and process for ammonia cracking catalyst activation

Abstract

An apparatus and process for the activation of catalyst material utilized in ammonia cracking can include an initial use of hydrogen and heat to perform an initial stage of catalyst activation and a subsequent use of ammonia and heat to perform a subsequent state of catalyst activation. The subsequent use of ammonia can be configured so that different catalytic material at different plant elements are activated in a pre-selected sequence to provide activation of the catalytic material utilized in different plant elements. Some embodiments can be configured to avoid excess temperatures that can be detrimental to equipment that can be positioned upstream of a furnace in some embodiments while also avoiding sintering of the catalytic material.

What is claimed is: 
     
         1 . A process for catalyst activation for ammonia cracking, the process comprising:
 feeding a first reactant comprising hydrogen to at least one pre-reactor positioned upstream of a furnace having at least one tube within a radiant section of the furnace such that the first reactant is passed through catalyst material of the least one pre-reactor and subsequently passed through catalyst material of the at least one tube within the radiant section of the furnace;   in response to detecting a first level of catalyst activation, ceasing the feeding of the first reactant and initiating feeding of a second reactant comprising ammonia to the at least one pre-reactor and the at least one tube within the radiant section of the furnace such that the second reactant is passed through the catalyst material of the least one pre-reactor and subsequently passed through the at least one tube within the radiant section of the furnace to fully activate the catalyst material of the at least one tube.   
     
     
         2 . The process of  claim 1 , wherein the feeding of the first reactant and the feeding of the second reactant occurs such that the catalyst material in an upstream portion of the at least one tube is fully activated, the catalyst material of the at least one pre-reactor is then fully activated, and then catalyst material in a downstream portion of the at least one tube is fully activated after the catalyst material of the at least one pre-reactor is fully activated and after the catalyst material in the upstream portion of the at least one tube is fully activated. 
     
     
         3 . The process of  claim 1 , wherein the feeding of the second reactant comprising ammonia occurs such that the catalyst material in a downstream portion of the at least one tube is fully activated last. 
     
     
         4 . The process of  claim 1 , comprising:
 mixing nitrogen with the ammonia of the second reactant so the second reactant has ammonia at a pre-selected ammonia concentration and/or the second reactant has a pre-selected flow rate; and/or   mixing nitrogen with the hydrogen of the first reactant so the first reactant has hydrogen at a pre-selected hydrogen concentration and/or the first reactant has a pre-selected flow rate.   
     
     
         5 . The process of  claim 1 , wherein the at least one pre-reactor includes a first pre-reactor having catalyst material within a vessel of the first pre-reactor and a second pre-reactor having catalyst material within a vessel of the second pre-reactor, the second pre-reactor being downstream of the first pre-reactor such that the second pre-reactor is between the at least one tube of the furnace and the first pre-reactor. 
     
     
         6 . The process of  claim 5 , wherein the feeding of the first reactant occurs such that:
 (a) the catalyst material in an upstream portion of the at least one tube is fully activated;   (b) the catalyst material of the second pre-reactor is fully activated; and   (c) the catalyst material of the first pre-reactor is fully activated; and   wherein the feeding of the second reactant occurs such that:   (d) the catalyst material in a downstream portion of the at least one tube is fully activated.   
     
     
         7 . The process of  claim 6 , wherein the catalyst material of the downstream portion of the at least one tube has a higher activation temperature than the catalyst material of the upstream portion of the at least one tube. 
     
     
         8 . The process of  claim 7  wherein the catalyst material of the downstream portion of the at least one tube has a higher activation temperature than the catalyst material of the first pre-reactor. 
     
     
         9 . The process of  claim 8 , wherein the catalyst material of the downstream portion of the at least one tube has a higher activation temperature than at least some of the catalyst material of the second pre-reactor. 
     
     
         10 . The process of  claim 1 , wherein the feeding of the first reactant also includes recirculating the first reactant through the at least one tube and the at least one pre-reactor for a first period of time. 
     
     
         11 . The process of  claim 1 , comprising:
 in response to detecting a first level of catalyst activation, venting of the first reactant while the second reactant is beginning to be fed toward the at least one pre-reactor and the at least one tube.   
     
     
         12 . An apparatus for ammonia cracking that is configured to facilitate catalyst activation, the apparatus comprising:
 a furnace having at least one tube that includes catalyst material within the at least one tube for cracking of ammonia, the catalyst material within the at least one tube having an upstream portion of catalyst material and a downstream portion of catalyst material;   at least one pre-reactor positioned upstream of the at least one tube, the at least one tube in fluid communication with the at least one pre-reactor;   the apparatus sized and configured so that:   a first reactant is feedable to the at least one pre-reactor and the at least one tube such that the first reactant is passed through catalyst material of the least one pre-reactor and subsequently passed through catalyst material of the at least one tube, and   a second reactant is feedable to the at least one pre-reactor and the at least one tube such that, in response to detecting a first level of catalyst activation, the first reactant is ventable and the second reactant is feedable to the at least one pre-reactor and the at least one tube such that the second reactant is passable through the catalyst material of the least one pre-reactor and subsequently passable through the at least one tube to fully activate at least some of the catalyst material of the at least one tube.   
     
     
         13 . The apparatus of  claim 12 , wherein the apparatus is configured so that the feeding of the first reactant occurs so that the upstream portion of the catalyst material of the at least one tube is fully activated first and then the catalyst material of the at least one pre-reactor is fully activated, and
 the second reactant is feedable to the at least one tube and the at least one pre-reactor such that the downstream portion of the catalyst material of the at least one tube is fully activated after the catalyst material of the at least one pre-reactor is fully activated and after the upstream portion of the catalyst material of the at least one tube is fully activated.   
     
     
         14 . The apparatus of  claim 12 , wherein the apparatus is configured so that the feeding of the second reactant occurs such that the downstream portion of the catalyst material of the at least one tube is fully activated last. 
     
     
         15 . The apparatus of  claim 12 , wherein the at least one pre-reactor includes a first pre-reactor having catalyst material within a vessel of the first pre-reactor and a second pre-reactor having catalyst material within a vessel of the second pre-reactor, the second pre-reactor being downstream of the first pre-reactor such that the second pre-reactor is between the at least one tube of the furnace and the first pre-reactor. 
     
     
         16 . The apparatus of  claim 15 , wherein the apparatus is configured so that the feeding of the first reactant occurs such that:
 (a) the upstream portion of the catalyst material of the at least one tube is fully activated;   (b) the catalyst material of the second pre-reactor is fully activated, and   (c) the catalyst material of the first pre-reactor is fully activated; and   the feeding of the second reactant occurs so that:   (d) the catalyst material in the downstream portion of the catalyst material of the at least one tube is fully activated.   
     
     
         17 . The apparatus of  claim 16 , wherein the downstream portion of the catalyst material of the at least one tube has a higher activation temperature than the catalyst material of the upstream portion of the catalyst material of the at least one tube. 
     
     
         18 . The apparatus of  claim 17 , wherein the downstream portion of the catalyst material of the at least one tube has a higher activation temperature than the catalyst material of the first pre-reactor; and
 wherein the catalyst material of the downstream portion of the at least one tube has a higher activation temperature than at least some of the catalyst material of the second pre-reactor.   
     
     
         19 . The apparatus of  claim 12 , comprising a reactant recirculation conduit arrangement positioned so that the first reactant is recirculatable from an outlet of the at least one tube to the at least one pre-reactor. 
     
     
         20 . An apparatus for ammonia cracking that is configured to facilitate catalyst activation, the apparatus comprising:
 a furnace having at least one tube that includes catalyst material within the at least one tube for cracking of ammonia, the catalyst material within the at least one tube having a more active portion of the catalyst material that is more active than a less active portion of the catalyst material;   at least one pre-reactor positioned upstream of the at least one tube, the at least one tube in fluid communication with the at least one pre-reactor;   the apparatus sized and configured so that:
 a first reactant is feedable to the at least one pre-reactor and the at least one tube such that the first reactant is passed through catalyst material of the least one pre-reactor and subsequently passed through catalyst material of the at least one tube, and 
 a second reactant is feedable to the at least one pre-reactor and the at least one tube such that, in response to detecting a first level of catalyst activation, the first reactant is ventable and the second reactant is feedable to the at least one pre-reactor and the at least one tube such that the second reactant is passable through the catalyst material of the least one pre-reactor and subsequently passable through the at least one tube to fully activate the less active portion of the catalyst material of the at least one tube.